The basking shark's common name derives from its habit of feeding at the surface, appearing to be basking in the warmer water there. It has anatomical adaptations for filter feeding, such as a greatly enlarged mouth and highly developed gill rakers. They weigh between 6,600 and 13,000 pounds. Although it has hundreds of small teeth, the basking shark does not use them when feeding; instead, it usually swims with its mouth open and catches whatever plankton is filtered through. It is one of three plankton-eating sharks along with the whale shark and megamouth shark.